Device-to-Device (D2D) technology is getting attraction because of the ability to offer new services, improve system throughput, and offer a better user experience. Potential use cases for D2D have been identified by the 3GPP Service and System Aspects working group 1 (3GPP SA WG1) in the 3GPP Technical Report (TR) 22.803. However, in order for D2D to be successful and applicable to various deployment scenarios, there is need to ensure that D2D works for both time-division duplexing (TDD) and frequency-division duplexing (FDD) systems.